Blackcest
by dwinchestersgirl
Summary: When Sirius and his twin sister Rhiana go driving around bored, a spark ignites and the siblings get closer than they could have possible imagined. A Canon/OC One-Shot.


**A/N: This is the first smut I've ever posted so I'm pretty excited to see how that turns out (: Please R&R I'd gladly appreciate it! Love you all! 3**

**Also: The character Sirius Black and the last name 'Black' belongs to none other than our lovely queen, Jo Rowling 3**

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Rhiana and Sirius drove around London in Sirius' 1978 Lil' Red Express. They were basically just doing this for sights, plus they were bored. They had started the punch buggy game by the time they had reached the outskirts of London.  
"Punch buggy red, no punch backs!" Rhi grinned, punching his arm as a red buggy drove past them.  
"What?" Sirius asked, glaring at her. He pulled over into a barren road and stopped the car, pulling his sister close and punching her back multiple times, playfully.  
"No punch backs! I said no punch backs!" Rhi laughed as he continued. This went on for a few more minutes, until Sirius had stopped and he was now straddling her and had her pinned down on the seat, both of them catching their breath.

"It was…a fucking game…" she replied, her chest rapidly rising and falling.

Sirius didn't reply. He looked down at his identical other, studying the features of her face, the bright blue eyes that gazed up into his, the soft pink lips that were always pursed, and the rosy tinge on her cheeks that got pinker in the winter. "A fucking game, you say?" he smirked down at her. She matched his smirk as he leaned down and pressed his lips firmly against hers, kissing her, his hands still pinning her down. Rhi let out a sigh and kissed back, closing her eyes slowly, feeling the smooth texture of his hard lips on her supple ones. Sirius released one of his hands from holding her down and let it trail down her face, past her neck, between her full breasts, to under shirt, where it snuck its way up, cupping her left bra covered breast and gently massaging it. Rhiana couldn't help but let out a soft moan as his rough hands handled her smooth skin. His other hand fully released her from his grip and he set it on the side of her face. Her hands slipped under his shirt, her hands traveling up his chiseled chest as she worked his shirt off. He easily unclasped her bra, dropping it somewhere in the truck. His lips traveled down her face, past her jaw line, over her collar bone and her breast, taking the nipple between his teeth and tugging gently. Rhi breathed heavily, slipping her hands down his back, into his pants and boxers, squeezing the warm globes that perfected his little arse. Sirius ground his hips on hers, making her release the moan she was holding back.

"Fucking hell, Rhi…" Sirius groaned, turned on even more by the soft moans escaping her lips. His hand slipped under her skirt, rubbing two long fingers over her panties, smirking when he felt how hot and wet she was.

"Horny for your own brother?" he asked, huskily, stroking her through her panties with his thumb.

"You know it…" Rhi replied, moaning. Sirius pushed the bottom of her undies to the side, slipping a finger inside of her eliciting a gasp from his twin as he began to move his finger in and out of her, rubbing her clit.

"You're so wet, you minx…" he growled, adding another finger and pumping faster, making her moaned louder, grinding her hips against his long fingers. He pulled his fingers out, looking her in the eyes as he licked his fingers clean. "And you taste so good…" he smirked, spreading her legs and lifting her hips, dragging his tongue over her wet slit. Rhi sunk into the upholstery of the seat as her brother's tongue delved into her folds, licking her of her sweet juices.

"Sirius…" she moaned, running her fingers in his soft, thick black hair, pressing him closer to her center. He pulled up, licking his lips and kissed her, letting her taste herself on his lips. He unbuckled his pants, positioning his length to her entrance and thrusted in quickly, kissing her to block the gasp she wanted to release. He didn't move for a moment, letting her get used to his thickness and length inside of her. He began thrusting slowly, kissing her, his hand massaging her breast, pinching her nipple a little.

"Sirius…harder…" she begged, arching her back as he obeyed, thrusting harder and faster, slamming into her. Kissing her couldn't hold back the loud gasps and moans of pleasure he drew from his sister as he fucked her hard. He continued, loving the feeling of how wet and tight she was around his throbbing cock.

"Fuck…you're so tight…" he groaned, thrusting until all of him was inside of her. Rhi screamed out in absolute pleasure, her body shaking with her building orgasm. Sirius moaned as he felt his orgasm hit, he came inside of her, quickly muttering the contraceptive charm. He kept thrusting, fucking her hard, hitting her core until he felt her hot walls tighten over his length and she orgasmed, screaming out his name. He pulled out, lying on top of her, the both of them panting heavily.

"Fuck me, Sirius…" Rhi breathed.

"I plan to..." he replied, catching his breath. "How about we take it back to your flat, for round two?" he smirked, a wicked twinkle in his eyes.

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**So I might post another chapter of it, based on how well this one goes! Let me know! xxx**


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